Thread roll fixture



April 18, 1967 B. D. BEDKER THREAD ROLL FIXTURE Filed Feb. 5, 1964 INVENTOR.

BRUCE .BEDKER BY u ATTORN United States Patent 3,314,262 THREAD ROLL FIXTURE Bruce D. Bedker, Mount Clemens, Mich., assignor to Leo W. Bedker, East Detroit, Mich. Filed Feb. 3, 1964, Ser. No. 342,144 7 Claims. (Cl. 72 104) The present invention relates to a thread roll fixture in which the thread rolls are interconnected by gearing, are laterally adjustable relative to each other, and in which means are provided to guard against the entry of chips into the gearing.

It is an object of the present invention to provide a thread roll fixture comprising a pair of thread rolls, a series of gears connecting the thread rolls to insure timed rotation thereof, means for adjusting at least one of the rolls relative to the other in a direction toward and away therefrom, a support including a pocket in which the gears are received, the pocket being laterally en- -larged to accommodate transverse movement of the gear connected to the adjustable roll, and a guard overlying the gear and including a fiange portion extending around its toothed periphery to prevent entrance of chips into the gear train.

It is a further object of the present invention to provide a thread roll including a pair of rolls, gears connected to said rolls, gearing connecting said gears, means for adjusting one of said gears and the roll connected thereto toward and away from the other roll and gear connected thereto, and chip guard means substantially surrounding the adjustable gear and movable therewith upon adjustment thereof.

Other objects and features of the invention will become apparent as the description proceeds, especially -when taken in conjunction with the accompanying drawing, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is a sectional view of a thread roll fixture taken substantially on the line 1 1, FIGURE 3, with parts broken away.

FIGURE 2 is a front elevation of the thread roll fixture shown in FIGURE 1, partly sectioned on the line 2 2, FIGURE 1.

FIGURE 3 is an end view of the fixture shown in FIG- URE l, partly sec-tioned on the line 3 3, FIGURE 1.

FIGURE 4 is a side elevation of the chip guard.

FIGURE 5 is a front elevation of the chip guard shown in FIGURE 4.

FIGURE 6 is an elevationaal view of a portion of the support body by itself.

FIGURE 7 is an elevational view of a cover or riser plate on a reduced scale.

The thread roll fixture disclosed herein is of the type fully described in the Bedker copending application Ser. No. 264,477, now Patent 3,110,202. For completeness herein however, the essential features of the fixture will be briefly described.

In general terms, the thread roll fixture comprises means for supporting a pair of opposed thread rolls with their axes substantially parallel and spaced apart a distance to accommodate a rotating work piece to be threaded. In practice, the axes of the thread rolls may be exactly parallel, or in some cases they may be provided to extend at a slight but predetermined angle with respect to each other. In operation the thread roll fixture is mounted for limited movement in a direction perpendicular to the axis of the work piece which is introduced between the thread rolls. The thread rolls are interconnected by gearing and the gearing is interconnected to the thread rolls with provision for limited lost motion so that as the thread rolls move to center position or beyond with respect to the work piece, the differential rotation required by such movement is permitted. In use, the thread roll'is positioned such that the rotating workpiece makes initial contact with one of the thread rolls and drives it in rotation. Rotation of this thread roll first takes up the lost motion in the gearing interconnecting the thread rolls and thereafter drives the other thread roll in the proper direction and at the required speed so that when it engages the opposite side of the work piece, its thread forming surface is moving in the same direction and at the same speed as the surface of the work piece. Therefore, the engagement between the surface of the work piece and the second thread roll takes place without disturbing the accurately timed rotational relationship between the thread rolls, and relative movement between the fixture and the work piece causing the work piece to move to or slightly beyond a center position with respect to the thread rolls results in the formation of a perfect thread.

In order to accommodate work pieces of different diameter, it is desirable to provide for relative adjustment between the thread rolls toward and away from each other. As fully explained in the aforementioned copending application of Leo W. Bedker, this is accomplished by providing a pair of eccentric bushings which are adjustable through equal increments so that a roll support shaft carried thereby may be moved generally toward and away from a second roll support shaft without however, disturbing its parallelism with respect to a pivot axis provided for the fixture. The other roll support shaft -has its end portions received in elongated slots so that it may be adjusted to exactly the required spacing, and parallelism may be maintained by insuring equal spacing between the two shafts at opposite ends thereof.

The requirement for adjustment of at least one of the roll support shafts toward and away from the other introduces a problem in the exclusion of chips from the gearing, and the present invention solves this problem by the provision of a specially formed chip guard designed to cooperate with the movable roll-coupled gear 0r gears so as to be movable therewith and to maintain chip exclusion in various positions of adjustment.

Referring now to the figures in detail, the thread roll fixture comprises body portions 10 and 12.

The body portion 10 comprises essentially a fiat plate havingan outer side and an inner side, the inner side in assembly being adapted to face the body portion 12. The inner side of the plate 10 is provided with a continuous gear pocket preferably formed by a plurality of intersecting pocket portions 14, 16, 1S, 20 and 22. At one edge thereof the body portion 1G includes a pair of generally parallel laterally extending arm or leg portions 24 and 26. It will be observed that the pocket portions 14 and 2.2 are located substantially within the leg portions 24 and 26 respectively.

In assembly, after insertion of gears as will subsequently be described, the pocket portions 16 and 20 are substanially covered by a riser or cover plate 28 the contour of which is seen in FIGURE 7 and the position in assembly of which is apparent from the remaining figures.

The body portion 12 includes an intermediate connector or spacer portion 30 adapted to abut the riser or cover plate 28, the cross-sectional shape of which is indicated by broken line 31 in FIGURE 6, and is provided at one edge with laterally extending parallel leg portions 32 and 34 which are respectively parallel to the leg portions 24 and 26 of the body portion 10. In assembly, as best seen in FIGURE 2, the leg portions 24 and 32 may together be considered as providing a single bifurcated leg, the furcations of which are formed by the leg portions 24 and 32. Similarly, the leg portions 26 and 34 may be considered together as constituting a single bifurcated leg, the furcations of which are formed by the leg portions 26 and 34.

Extending between the leg portions or furcations 24 and 32 is a roll shaft 36. Extending between the leg portions or furcations 26 and 34 is a roll shaft 38. Mounted on the roll shafts 36 and 38 are thread rolls a portion of one of which is indicated at 40.

In order to insure the required timed rotation of the thread rolls 40, a series of gears is provided comprising roll-coupled end gears 42 and 44, a central gear 46, and intermediate gears 48 and 50. The end gears 42 and 44 are connected by suitable lost motion connections to the adjacent thread rolls, all as clearly set forth in Bedker Patent 2,701,484. It will be observed that shafts 52, 54 and 56 are provided for the gears 4S, 45 and 5t) respectively.

Opposite ends of the shaft 33 are mounted in eccentric openings in bushings 58 and 60 and means are provided for insuring that the two bushings 58 and 60 are mounted in exactly the same position. The means for insuring this may for example, be of the type disclosed in the aforesaid copending Bedker application, and insures that when the bushings are properly positioned, the shaft 3S retains its orientation in parallelism with the axis of a pivot mounting (not shown) for the entire thread roll fixture. If the bushings 58 and 60 are for example designed to occupy one of two positions 180 apart, it will be apparent that when both bushings are turned the shaft 38 will be moved toward or away from the shaft 42 by an amount equal to twice the eccentricity of the central opening in the bushings.

The shaft 36 is intended to be adjusted continuously Y relative to the shaft 38 and for this purpose opposite ends of the shaft 36 are received in elongated slots 62 formed in the leg portions or furcations 24 and 32 respectively. The shaft 36 may be adjusted by suitable means such as screws indicated generally at 64 and 66. By insuring that opposite ends of the shafts 36 are equidistant from corresponding ends of the shaft 38, parallelism between the shafts 36 and 38 is insured. Since parallelism between the shaft 38 and the pivot axis of the thread roll xture was insured by the mechanism previously described, this means that parallelism will always exist between the pivot axis of the fixture and the shafts 36 and 38. In cases where a predetermined very small angular relationship is required between the shafts 36 and 38, this is accomplished by providing the elongated slots 62 in the leg portions or furcations 24 and 32 of the xture out of exact alignment by the amount required to produce the desired angular relationship.

Since the aforesaid adjustment between the thread rolls, or more specifically, of each of the thread rolls with respect to the other, requires a corresponding movement of the rollcoupled gears 42 and 44, it is apparent that it is necessary to provide the pocket portions 14 and 22 with sucient lateral dimension to accommodate such movement. It will further be understood that the adjustment of the axes of the shafts 36 and 38 is in a direction generally tangential to arcs concentric with the axes of the shafts 52 and 56. Since the amount of this adjustment is relatively small, the path of adjustment does not depart appreciably from the arcs and hence, the adjustment of the shafts may be considered as taking place in arcs concentric with the axes of the shafts 52 and 56. This of course preserves the proper meshing relationship between the gears of the train.

However, the provision of lateral enlargement to the pocket portions 14 and 22 presents a diiculty in chip control since these pockets are not covered by the cover or riser plate 28 and hence, unless special provision is made, chips could enter into these pockets and be carried around into the meshing zone of the teeth of the gears. In order to eliminate this difficulty, a special construction of roll-coupled gears 42 and 44 is provided and special CII CII

chip guards 70 are provided. As best seen in FIGURES 2 and 3, the gears 42 are provided at the side thereof adjacent the outer side of the pocket with smooth surfaced cylindrical elements 72. These elements may be integral with the gears or they may be separate elements suitably connected thereto. In any case, the smooth outer diameter of the cylindrical elements or portions 72 is substantially equal to the outer diameter of the toothed portions of the gears 42 and 44.

The guards 7d as best seen in FIGURES 4 and 5, comprise thin flat plate portions 74 apertured as indicated at 76 for the reception of the shaft 52 or 56 and have lateral extensions 78 shaped to extend into the pocket portion 14 or 22, this extension having an enlarged circular opening 80 therein dimensioned to fit closely with respect to the outer surface of the elements 72 so as to prevent the entry of chips therebetween. In addition, the guards 70 include a continuous laterally extending flange 82 which extends from a point at one side of the pocket portion 16 to and completely around the pocket portion 14 and to a point at the opposite side of the pocket portion 16. As seen in FIGURE 3, the flange extends to the bottom of pocket 14.

It will be apparent from FIGURE 1 that the pockets 14 and 22 are dimensioned to permit substantial lateral movement of the extensions 73 of the guards therein. The portions of the continuous flange 82 which extend into the pocket portions 16 and 20, 0r the opening 76 in the guards, or both, constitute guides which provide for generally annular adjustment of the guards about the axes of the shafts 52 and 56 when the shafts 36 and 33 are adjusted.

Since the surface of the opening 8% conforms closely to the surface of the cyindrical element 72, the entry of chips into the teeth of the gears 42 and 44 is prevented at this point. Since the flange 82 is continuous around the outer side of the gears 42 and 44 `and extends into the pocket portions 16 and 26, any chips which enter the pocket portions 14 and 22 are prevented by the flange from entering into the toothed portions of the gearing.

The presence of the guards 70 in association with the gears 42 and 44 and the adjacent intermediate gears 48 and Sit, does not in any way interfere with the operation of the rolls nor with the adjustment of the rolls required to accommodate different sized work pieces. The guards may be formed of sheet metal but the conguration thereof lends itself most eiciently to fabrication of the guards from a suitable plastic material such as nylon. In any case, the thickness of the guard need not be great and excellent results have been obtained in which the guard is formed of nylon having a thickness of approximately .020.

What I claim as my invention is:

1. Thread rolling apparatus comprising a body having two arms, an assembly carried by each of said arms comprising a shaft, a thread roll and a gear coupled to said roll, the shafts on said arms being substantially parallel, means for insuring timed rotation of said rolls comprising at least one intermediate gear in mesh with one of Said roll-coupled gears, a first pocket in said body open at one end and receiving the shaft and gear of one of said assemblies, said pocket being laterally enlarged to provide for movement of the roll-coupled gear therein toward and away from said other assembly, a second open-ended pocket in said frame laterally intersecting said first pocket, means in said second pocket mounting the intermediate gear in mesh with the roll-coupled gear in said rst pocket for rotation about a xed axis, said one assembly having a cylindrical surface located substantially at the open end thereof, a movably mounted chip guard comprising a at plate overlying the gear in said second pocket and having a lateral extension toward said tirst pocket provided with an opening interfitting with said cylindrical surface and movable therewith upon movement of the said assembly in said rst pocket and forming a closure therewith preventing entry of chips into contact with the roll-coupled gear in said first pocket, said guard having a iiange extending to the bottom of said first pocket and extending around said first pocket between the lateral intersection between said first and second pockets at the side of said gear remote from said second pocket and extending iuto said second pocket.

2. Apparatus an dened in claim 1 in which said second pocket has 'a cylindrically formed side Wall and the portions of said ange extending into said second pocket are cylindrically shaped to intertit therein.

3. Apparatus as dened in claim 1 in which three intermediate gears are provided, said body having three separate but open-ended laterally intersecting pockets in which said three intermediate gears are received, and a stationary cover substantially closing the open ends of said three pockets.

4. Apparatus las defined in claim 1 in which said second pocket has a cylindrically formed side wall, the portions of said ange extending into said second pocket are cylindrically shaped to interit therein, and in which three intermediate gears are provided, said body having three separate but open-ended laterally intersecting pockets in which said three intermediate gears are received, and a stationary cover substantially closing the open ends of said three pockets.

5. Apparatus as dened in claim 1 in which said cylindrical surface is provided on the outer end of said rollcoupled gear in said iirst pocket.

6. Apparatus as defined in claim 1 in which said body is provided with a pocket for each of said roll-coupled gears, and in which like chip guards are provided for both of said pockets.

7. Apparatus as defined in claim 1, the gear in said vsecond pocket having a shaft, said plate having a circular opening receiving the shaft Of said gear in said second pocket land being pivotally mounted thereby for arcuate movement about the axis of the shaft in said second pocket.

References Cited by the Examiner UNITED STATES PATENTS 727,761 5/ 1903 Eberhardt 29-965 1,193,487 8/1916 'Preston 74-566 1,753,092 4/1930 Nixon 74-566 2,862,404 12/1958 Odermann 74-566 3,110,202 11/1963 Bedker 72-248 CHARLES W. LANHAM, Primary Examiner.

H. DIETER HOINKES, Assistant Examiner. 

1. THREAD ROLLING APPARATUS COMPRISING A BODY HAVING TWO ARMS, AN ASSEMBLY CARRIED BY EACH OF SAID ARMS COMPRISING A SHAFT, A THREAD ROLL AND A GEAR COUPLED TO SAID ROLL, THE SHAFTS ON SAID ARMS BEING SUBSTANTIALLY PARALLEL, MEANS FOR INSURING TIMED ROTATION OF SAID ROLLS COMPRISING AT LEAST ONE INTERMEDIATE GEAR IN MESH WITH ONE OF SAID ROLL-COUPLED GEARS, A FIRST POCKET IN SAID BODY OPEN AT ONE END AND RECEIVING THE SHAFT AND GEAR OF ONE OF SAID ASSEMBLIES, SAID POCKET BEING LATERALLY ENLARGED TO PROVIDE FOR MOVEMENT OF THE ROLL-COUPLED GEAR THEREIN TOWARD AND AWAY FROM SAID OTHER ASSEMBLY, A SECOND OPEN-ENDED POCKET IN SAID FRAME LATERALLY INTERSECTING SAID FIRST POCKET, MEANS IN SAID SECOND POCKET MOUNTING THE INTERMEDIATE GEAR IN MESH WITH THE ROLL-COUPLED GEAR IN SAID FIRST POCKET FOR ROTATION ABOUT A FIXED AXIS, SAID ONE ASSEMBLY HAVING A CYLINDRICAL SURFACE LOCATED SUBSTANTIALLY AT THE OPEN END THEREOF, A MOVABLE MOUNTED CHIP GUARD COMPRISING A FLAT PLATE OVERLYING THE GEAR IN SAID SECOND POCKET AND HAVING A LATERAL EXTENSION TOWARD SAID FIRST POCKET PROVIDED WITH AN OPENING INTERFITTING WITH SAID CYLINDRICAL SURFACE AND MOVABLE THEREWITH UPON MOVEMENT OF THE SAID ASSEMBLY IN SAID FIRST POCKET AND FORMING A CLOSURE THEREWITH PREVENTING ENTRY OF CHIPS INTO CONTACT WITH THE ROLL-COUPLED GEAR IN SAID FIRST POCKET, SAID GUARD HAVING A FLANGE EXTENDING TO THE BOTTOM OF SAID FIRST POCKET AND EXTENDING AROUND SAID FIRST POCKET BETWEEN THE LATERAL INTERSECTION BETWEEN SAID FIRST AND SECOND POCKETS AT THE SIDE OF SAID GEAR REMOTE FROM SAID SECOND POCKET AND EXTENDING INTO SAID SECOND POCKET. 